An activated carbon filter for separating pollutants, e.g., dioxins and furans from flue gases before they enter the flue has been known from EP-B1-0,490,202. To absorb these pollutants, activated carbon is mixed with 30-40 vol. % of water in a filter vessel, and the flue gases are passed through the activated carbon-water mixture in the form of fine chains of bubbles. The filter vessel has a perforated partition as a gas distributor. The activated carbon sludge saturated with pollutants is drained off and replaced by correspondingly adding dry activated carbon and water.
The prior-art activated carbon filter has been tested in field tests, and it has met the requirements in terms of the filtration efficiency.